Modified Yeast Ferments Biomass Xylose

Producing biofuel on a useful scale requires efficient fermentation of cellulosic plant material. The sugars glucose and xylose are the most abundant carbohydrates found in hemicellulose. The yeast most commonly utilized for industrial fermentation – Saccharomyces cerevisiae – can ferment glucose but not xylose.

By studying the genomes of wild strains of yeast capable of utilizing both sugars, researchers hope to identify genes capable of enhancing fermentation. The ultimate goal is to create a genetically modified ‘super-strain’ ideal for industrial ethanol production.

Description

A UW–Madison researcher and others have developed an S. cerevisiae strain genetically engineered with xylose utilization genes from another yeast, Scheffersomyces stipitis. The new strain (GLBRCY35) has been made to express S. stipitis genes XYL1, XYL2 and XYL3, which are known to improve xylose fermentation.